% clear,clc
 x=[];y=[];
H=imread('赛道.png');
H=H(250:650,:,:);
imshow(H)
while 1
    pause();
    [i j]=ginput(1);
    x=[x;i];y=[y;j];
end

x=flipud([x;x(1)]);
y=flipud([y;y(1)]);